Barcelona-based Ferran Fages is known both for his lyrical acoustic guitar playing (on solo discs such as Cançons a per un Lent Retard and Al Voltant d'un Para/'lel) and for hard-edged electronics (with groups such as Cremaster and Octante). His work in Ap'strophe—a duo with Athens-based zither player Dimitra Lazaridou-Chatzigoga—is an intriguing combination of these two sides of his music: there is plenty of resonant acoustic playing, but this is set against both the metallic textures of Lazaridou-Chatzigoga's zither and both players' sometimes harsh electronic extensions of their instruments' timbres. The duo had been playing together for four years when they recorded Corgroc in Barcelona in December 2008, developing what one reviewer describes as "a quite breathtaking music that sounds something like what eels produce in the stomach."

The album consists of two tracks titled after the first line of an e.e. cummings poem. The first, "spring," lasts just under eight minutes; the second, "is like a perhaps hand," extends to nearly forty minutes. As one critic observes, the duo pursues "a pathological aversion to playing the next expected sound," and repeated listens reveal "with what rigor and musicality the duo pursue that subterfuge, and actually how much their sound world is made of steel wire and wood after all."

One reviewer notes that "pure acoustic passages are overwhelmed by orgies of sound where it is difficult to determine what is acoustic and what is electronic. On the album it says that they play guitar and zither, but the instruments are treated as if they were loudspeakers." The music doesn't stray far from their first album (Objects Sense Objectes, 2009), but perhaps there is a slightly more fragile feel to this release, a more simple structure. The opening track begins with what one listener describes as "fingernails scraped down a blackboard" sounds—abrasive textures that form the foundation of their distinctive approach.

A particularly insightful review captures the unexpected power of the recording: "Given the way that the music suddenly develops from subdued textural minimalism to something of genuine, sustained emotional intensity, I find myself rather at a loss as to how to sum up the album's impression on me... I was actively disturbed by the music's unexpected cumulative power and pull – caught off-guard, one might say." The reviewer concludes that "'Corgroc' is an unusually compelling recording, one which evolves from being 'just' a fine piece of improvisation into something much more: a work of real and remorseless power."

The duo's approach brings "a noise sensibility to their quiet sound spectrum," working in what one listener characterizes as "high-intensity/low volume" territory. Essential listening for those interested in the outer limits of acoustic string improvisation, where the boundaries between acoustic and electronic, between lyrical and abrasive, become productively blurred.